Multiple telephone-transmitter.



G. B. EGNER & J; G. HOLMSTBD M. MULTIPLE TELEPHONE TRANSMITTER. rum-r10:11mm mm. m, 1209.

1,023,557, Patented Apr. 16, 1912.

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Specification Letters Patent.

Patented Apr. 16. 191 2.

Aii nmuon am n w 1a, was, Serial in. 512,409.

known that..we, {Jenn Eran, FxGNlFlH, a subjeet of theKing of Sweden,and vesi- Elf; file giui igflfln fifilstmkhol-mi in gdoino ffiu eden,andJmmN GLXXAR Homrs'rnihn a subject oftheKing of Sweden,

l have invented certain i resistanee int .aeitv of IHlUJUH'SlI'OIl"currents are i nah i u i n a I new and "useful "Improvementsin Multiple1 0 llglephone-Trimamitters, of whieh the follle S I]0CGSS&l1fy for a:powerful telephone atrnnsmitter. In order to attain as great fl-Jl'nlllGllSllfi possible in the ll'rmsll'fillt'l' i h wi th'out too greatnormal i'esis'tail-(te two or g series. as well known.

more transmitter have been emmeeted in The effect of such a connectionof the-tranemilters however often in 1C5}; than that of a singletranmuitter due l to .1'e:1 pn easily understood. Owing to thefart'tlialthe dislanees between the mouth of g the telephoning permu andthe diapln'uum ofiphetransn ittefl are not exartly the same am thequalities of the diupln'an'rns and the wells ofjhe transmitteraredill'erenl. how ,t'dft'l;Jifllftilhll) the mild purl-s areinarnlfartilreql. in lmrherenee iirthe eleetri-c,oeeillatimis Leffected. whirl) reduees the result of the -i:i iperutiq n of thetrausmitt-m'. .Sno'tlier arrangement for the same ]nnpo.-:econsists inProviding two or more transmitters he hind the name diaphragm. .llul theresult of the jiillll-.;ll'l'1lllfi't'llll'lll' haw hitherto not been)HllbfflClOlj' due l'i the impossibility of ruusill g tlnlHHJHllllf-(l'eells to euiiperale. The uuid diiuphrmn i. divided inluisonornuis'figurw. .m that ditl'ereut parts of the d n pln'ugm weillale in adifl'erel-it \\'uat the same moment.

50 ward at another cell during the same moment. thus reducing theprewu're against the carbon granules of that cell and increasing theresistance which results in the said cells counteracting each other andthe object aimed at being missed. The said lack of cooperation of thecells of multiple transmittiers hitherto used can, evidently, not'beremoved adg'usting the pressure between the mutants of the cells.

invention relates to a transmitter with two or more cells so constructedthat the cells are caused to coiiperate, which object is aimed bycombining the cells with a strai diaphragm. By straining the diaphragmit"in caused to oscillate uniformly and ranch manner that it oscillateswith the greater-.1 amplitude at its center part. The cells are soarranged that they receive and taransiorm into variations of the elwtricresistance the ver) same vibrations, made by the neuter part of thediaphragm, so that there is a perfect synchronism in all the eells.Owing to the said syrvhronism it is poysible to so adjust the [)l't surebetween the contacts of each cell that the sum ofrthe aet ions of thecells is a maximum.

The :n-rompanying drawing shows in a rims setrlimi part of a multipletransmitter arranged in aecordanre with this invention.

The diaphragm 1 is jammed between the easing 52 of the transmitter and aring 3,

lined to the easing in any suitable manner.

4 is a ring-shaped inner edge of the casing 2. agaiimt which thediaphragm 1 in bearing. The straining of the diaphragm is effected aring 5 forcing the diaphragm into the groove ohetween the edge 4 and thewall of the (a-sl ng 2. The said ring 5 is forced inward by means oftlnunb-nuts 7 or in any other suidarh-le manner and strainstheidiaplrragm mrifnrmly from its (miter outward. [unread of fii'xh-rgeach of the movable electrodes of the cells separately tothediaplnrzrgiu 1. a disk 8 is fixed to the diaphragm by meamn of ascrew pin 5) at the center of the same. At the periphery of the saiddisk 8 a plurad iity of electrode (links or pieces 10 i are fixed one ofwhich is shown in the draw- 17 of our ofl lie eells ill beredueed owingm 1 and full synehroniem at all the ing. A hollow perforated cylinder 11of steel or any other hard material is mounted between the disk 8 andthe diaphragm 1. (knlse'q uenfily. the said disk 8 with the electrode 10will vibrate just in the same manner as the center part of the('liafhragm isks 10 will be attained so that the said disks 10 moredownward simultaneously and upward simultaneously, thus effecting thesame variations in all the cells during the same periods. The electrodedisks 10 are insulated filom the disk 8 and mutuall and are gonnected.

by conductors 12 with the insulated clamping nuts 13 on the outer sideof the diaphragm 1. Each of the electrodes 10 ex tends downward into asubjacent' cup 14. The said cups, which form the other electrode of therespective cells, are insulated mutually and from the other parts of theapparatus, the cups being for that reason supported by plungers 15,fitting in cylinders 16, which are mounted in a plate 17 of aninsulating material and common to all the said cylinders 16. Each of thecups 14 can be adjusted with relation to the electrode 10 z'. e. thepressure between the electrode 10 and the carbon granules 18 in the cupcan be adjusted to the most suitable one. As a screw 19 hearing againstthe lower end of the plunger 15 is moved inward the plunger 15 and thecup 14 are raised, and as the screw is moved outward the plunger 15 andthe cup 14 will follow the same owing to the pressure of a spring 20fixed to a stationary part of the apparatus and acting downward upon theplunger 15. The said spring 20 also serves as a conductor between thecup 14 and the respective outer contact or clamping nut 21.

l/Vhen the described transmitter is to be adjusted the cells areseparately and in turn connected with the circuit and adjusted by meansof the corresponding screw 15), so that the greatest elt'ect is gained.in order that absolutely the same adjustment, may be .made 111' all thecells the said adjusting operation must be effected in such'manner, thatafter each of the cells has once been adjusted the adjusting operationis again started with the first cell and is then continued cell by cell,thesaid operatidn being thus repeated two or three times. In the saidmanner the cells are caused to cooperate exactly and a specially greateffect is gained.

\Vhen each of the cells has been adjusted in the described manner bymeans of the screw 19, so that there is the same pressure in all thecells, it may be necessary during the operation of the transmitter tosome what increase or decrease the said pressure. The adjusting of'eachcell separately for the said purpose would. evidently, be verytimeconsinning and un'practical, as each cell then must be adjusted atleast twice. For that reason the transmitter in question is providedwith a de ice, by HIGH-1130f which all'the cells can be uniformly andsimultaneous y adjusted, after the same pressure has beeircffected inall the cells. For the said purpose the insulating plate 17, supportingall the plungers 15 of the cups or cells 14 can be moved 11 Ward anddownward (without being rotated by rotatingaring22. The said ring 22,which can be rotated horiz0ntally, is prevented from moving verti callyby screw-pins 23, engaging a groove provided in a stationary boss 21inclosing the plate 17. A screw-threaded ring 25 fixed to the plate 17and engaged by the ring 22 is caused by the rotated ring 22 to movevertically parallelly to itself, thus raising or lowering the plate 17and all the cups 14. The plate 17 is prevented from rotating by thesprings 20 and by one or more vertical ribs 26 engaging grooves 27provided in the said boss 24, for instance.

Having now described our invention, what we claim as new and desire tosecure by Letters Patent is:

1. In multiple telephone transmitters, the

combination of a diaphragm uniformly' strained from its center towardits periphery, a disk firmly secured to in-eXtended surface of thecentral portion of the diaplu'agm, substantially as great as the saiddisk, and a plurality of rigid members fixed to the said disk andforming one of the electrodes of respective transmitter cells.

2. In multiple telephone transmitters, the ron'ihiuation of a diaphragmuniformly strained from its center toward its periphcry, a disk fixed tothe center part. of the diaphragm, an interposed piece of hard materialbetween the diaphragm and the said disk. and of substantiallythe samediameter as the disk, the said interposed piece bearing with its endsagainst the diaphragm and the disk respectively, and a plurality ofrigid members fixed to the aforesaid disk and forming one of theelectrodes of respective transmitter cells.

3. [n telephone transmitters, the combination of a diaphragm uniformlystrained outward from its renter, a plurality of members forming one ofthe electrodes of respectivc transmitter cells, a disk fixed to thecenter part of the diaphragm and supporting the said electrode-members,and a hollow interposed piece of hard material between the diaphragm andthe said disk, and arranged like a grating, substantially as describedand for the purpose set forth.

in witness whereof. we have hereunto igned our names in presence of twosubscvibing witnes es.

CARL run. sorta. JHHAN GUNNAR HOLMSTROM.

Witnesses:

ANNA [.tinrusrutim, Ronirirr .\l'l'liFI-'Rl'IN.

